class Solution {
public:
    int minCostClimbingStairs(vector<int>& cost) {
        int n=cost.size();
        vector<int> dp(n+3);
        dp[0]=dp[1]=0;
        for(int i=2;i<=n;i++)   
            dp[i]=min(dp[i-2]+cost[i-2],dp[i-1]+cost[i-1]);

        return dp[n];
    }
};
